Jansje Dekker was the first born child of Levie Abraham Dekker and Rebecca van Vliet. She was unmarried.
Jansje was born into a family with in total seven children. Her brother Elias died in 1929 but her brothers Abraham, Salomon (called Leo) and Jacob survived the Holocaust. Her sisters Johanna and Emma have been killed in the Shoah.
Jansje lived in Amsterdam at Plantage Doklaan but spent much time with her sister Johanna, who lived nearly around the corner at Plantage Parklaan.
Toghether with her sister Johanna, Jansje Dekker was registered in Camp Westerbork on 4 February 1943 and deported to Auschwitz on 9 February, where both upon arrival there on 12 February 1943 immediately have been killed.
City Archive of Amsterdam, archive cards of Jansje and Johanna Dekker and the file cabinet of the Jewish Council of Amsterdam, cards of Johanna and Jansje Dekker.